Annexon, Inc. (ANNX)

Several events have impacted Annexon, Inc.'s stock price in the past six months. The company reported $188.7 million in cash and short-term investments in Q3 2025, extending its operating runway into late Q1 2027. A public offering in November 2025 raised approximately $80.4 million, leading to a stock price drop due to dilution concerns. Enrollment for the Phase 3 ARCHER II trial for vonaprument was completed ahead of schedule. Annexon submitted a Marketing Authorization Application to the European Medicines Agency for tanruprubart for Guillain-Barré Syndrome. Annexon outlined 2026 as a pivotal year with detailed registrational milestones across its lead assets. The stock experienced an 8.73% decline between January 2, 2025, and December 31, 2025, but increased by 4.17% in the month leading up to January 9, 2026.

Analysis of the past four years suggests a seasonal pattern for Annexon, Inc., with a "Buy Date of May 25 and a Sell Date of September 18" historically resulting in a geometric average return of 34.22% above the S&P 500 Total Return Index. This seasonal timeframe has shown positive results compared to the benchmark in four of those periods, significantly outperforming the relative buy-and-hold performance of the stock by an average of 74.94% per year. This seasonal strength aligns with the broader Healthcare sector's seasonal period, which typically runs from April 25 to December 4.

Annexon, Inc. is a clinical-stage biopharmaceutical company focused on developing therapies for classical complement-mediated disorders. Their scientific approach involves inhibiting C1q to reduce neuroinflammation and tissue damage. Key product candidates include tanruprubart (ANX005) in Phase 3 for Guillain-Barré Syndrome, vonaprument (ANX007) in Phase 3 for geographic atrophy, ANX1502 in Phase 1 for autoimmune indications, and ANX009 in Phase I for lupus nephritis. The company was incorporated in 2011 and is headquartered in Brisbane, California.

Annexon, Inc.'s geographic footprint is defined by its global clinical development and regulatory activities. The company is pursuing regulatory approvals in the United States and Europe for its lead candidates, with a European MAA submission for tanruprubart expected in January 2026 and a U.S. BLA planned for 2026. Vonaprument is in a global Phase 3 trial with defined U.S. and European registration paths. While headquartered in Brisbane, California, the company aims for international market reach upon successful drug development and approval.

Annexon, Inc. generally has a positive brand reputation, particularly among analysts, with a consensus rating of "Moderate Buy". Its news sentiment score is 0.54. However, as a clinical-stage biopharmaceutical company with no current revenue and significant net losses, it faces inherent risks in the biotech sector. The dilution caused by the November 2025 public offering led to a short-term stock price drop, reflecting investor anxiety. There have been no explicitly negative events severely impacting its reputation in the past year beyond the typical challenges and market reactions associated with a pre-commercial biotech firm.

Annexon, Inc. is primarily an institutionally-owned stock. Institutional shareholders held approximately 84.75% of the company's stock, with insiders owning 23.17% and retail investors holding 0.00%. Other data indicates institutional ownership around 100.05% of the float as of late 2025, or approximately 44.49% to 52.29% of the company's stock, with insiders holding around 7.41% and public companies/individual investors holding 7.80% to 40.29%. Major institutional owners include Fmr LLC, BlackRock, Inc., Vanguard Group Inc., Bain Capital Life Sciences Investors LLC, Redmile Group, LLC, Bvf Inc/il, Bellevue Group AG, Morgan Stanley, and Millennium Management Llc. Bain Capital Life Sciences Investors LLC is the largest individual Annexon shareholder, owning 11.10 million shares, representing 9.28% of the company.